问题
解答题
求值: (1)2-
(2)lg5(lg8+lg1000)+(lg2
|
答案
(1)原式=
1 | ||
|
1 | ||
|
2 |
| ||
2 |
2 |
2 |
(2)原式=lg5(3lg2+3)+(
3 |
6 |
100 |
=3lg5lg2+3lg5+3lg22-lg6+lg6-2
=3lg2(lg5+lg2)+3lg5-2
=3(lg2+lg5)-2
=3-2=1.
求值: (1)2-
(2)lg5(lg8+lg1000)+(lg2
|
(1)原式=
1 | ||
|
1 | ||
|
2 |
| ||
2 |
2 |
2 |
(2)原式=lg5(3lg2+3)+(
3 |
6 |
100 |
=3lg5lg2+3lg5+3lg22-lg6+lg6-2
=3lg2(lg5+lg2)+3lg5-2
=3(lg2+lg5)-2
=3-2=1.